flanged ball bearing industry , market demand for high-end bearing is growing, such as machine tool bearings , aerospace bearings, high-speed precision bearings, wind power bearings, rolling bearings , high-speed rail bearings, turbocharger bearings , and so on .
2014年7月31日星期四
miniature ball bearings Make two groups to purpose
2014年7月30日星期三
miniature ball bearings Irregular noise
2014年7月29日星期二
high speed bearing by rolling vibration
2014年7月28日星期一
LYHY flanged ball bearing eliminate cage sound
2014年7月25日星期五
miniature ball bearing Scope of application
2014年7月16日星期三
high speed bearing requirements
1) high resistance to plastic deformation capacity,
2) anti friction, wear and high performance,
3) the rotating precision and high dimensional accuracy,
4) good dimension stability,
5) a long service life and high reliability.
For Liner Motion Bearings working under special conditions, there are special requirements, such as high temperature performance, low temperature resistant performance, corrosion resistance and water resistance etc..
The working environment and the performance of the miniature ball bearings
The miniature ball bearings is composed of an inner, outer ring, rolling body (ball, roller or needle roller and cage) is composed of four parts, in addition to maintain the reactor, the rest are composed of bearing steel. When the bearings, bearing inner, outer ring, rolling bearing body bear the high frequency, stress function. Bearing working conditions are very complicated. Load concentration in a small area of the rolling body. Theory for the ball, in a point; and the roller is in a line, and the rolling body and the ring contact area is very small (a point / line contact), so the bearing parts in the work, the rolling body and the ring surface per unit area to bear great pressure in general, up to 1500 - 5000N/mm2; Series radial ball bearings rotation, but also bear the role of centrifugal force, the force increases as the speed increases; a rolling body and a ferrule exists not only rolling, and sliding, so there is friction between the roller and ring. The comprehensive role in the above several stress, fatigue strength of low position on the surface of ring or rolling of the first fatigue crack, finally forms the fatigue spalling, the bearing failure. Bearing normal damage form is the contact fatigue damage, common and plastic deformation, indentation, wear, cracks etc.
Check the flanged ball bearing quality of four points
First, turn tone with a stethoscope to check flanged ball bearing, a metallic noise, strong noise, irregular, abnormal sound. Due to poor lubrication, shaft or housing poor accuracy, bearing damage, foreign intrusion etc..
Second, the bearing temperature, generally according to the external temperature of the bearing seat to speculate. But the direct measurement of the bearing outer ring with oil hole temperature more accurately. Thrust Ball Bearings temperature, from a running start rising, usually 1~2 hours after the temperature stability. Bad if the bearings are mounted, the temperature will rise sharply, abnormal high temperature. The reason such as excessive lubricant, the self aligning ball bearing clearance is too small, poor installation, sealing device too much friction. High speed rotating occasions, lubrication structure, choice is also the cause of the error.
Guide roller, guide, slider, linear bearings, miniature ball bearings series of deep groove ball bearing series needle roller (roller) bearings, thrust ball bearings
Third, small machinery can be rotated by hand, to confirm whether the rotation is smooth. Check the project caused by foreign body, scars, indentation running sluggish, due to poor installation, mounting process arising out of the bad moment is not stable, because the clearance is too small, installation error, sealing caused by friction force is too large and so on. If there is no anomaly can begin power operation.
Fourth, large machinery can not be manually rotated, so the no-load starting immediately after power cut, mechanical idling, check whether the vibration, noise, rotating parts are in contact and so on, confirmed no abnormal, into the dynamic operation.
2014年7月11日星期五
Double row ball slewing bearingand shaft installation inspection method
2014年7月9日星期三
Tapered roller bearings and high speed bearing installation
2014年7月8日星期二
mounting of flanged ball bearing
2014年7月4日星期五
Effect of temperature on bearing life
Bearing in the work,self aligning bearings its size may be changed by changing the structure of the material. This transformation was affected by temperature, time and stress.
In order to avoid the dimensional change not allowed due to changes in material structure in the work, bearing materials must go through a special heat treatment.
According to the different types of bearings, bearing in standard harden ability and induction quenching heat treatment of steel, the recommended maximum working temperature is between 120 to 200 degrees. There is a direct relationship betweenthe maximum operating temperature and the heat treatment process can be achieved.agricultural bearings If the normal working temperature higher than the highest temperature of someapplication suggestions, bearing should choose stable series high. If the bearing of continuous working in high temperature, load capacity of the bearing may need tomake adjustments.
2014年7月2日星期三
Influence of bearing structure on the vibration and noise(two).
4 holder of sound
Keep the free vibration of frame and the rolling body or ring phase impact will send this noise in the bearings rotate process. It may appear in all kinds of bearing, but itssound pressure level is not too high and the low frequency. Full complement cylindrical roller bearing Its characteristic is:
A. stamping cage and plastic holder can be generated
B. either oil or grease will appear.
C. when the outer ring bearing the bending moment is most likely to occur.
D. radial clearance large easily.
Because the cage pocket clearance and the holder and the ring gap is inevitable in bearing product to exist, self aligning bearing
thus completely eliminate cage sound is very difficult, but can reduce the assembly error, gap optimum and cage movement to improve.
Another cage special sound is due to the holder and the other bearing parts leading between the rubbing surfaces caused maintain self-excited vibration and noise frame.Stamping of deep groove ball bearing retainer is thin, curved in the radial and axial in-plane stiffness is low, the overall stability is poor, will the bearings rotate at high speed due to bending deformation caused by self-excited vibration, "beep".
When the bearing under a radial load and oil poor performance situation, at the beginning of operation "Kacha, Kacha hear noise", which is mainly due to the rolling body left in the load zone, noise suddenly accelerated and cage collision by rolling,the sound of impact can not be avoided but with running for a period of time will disappear.
To prevent the holder noise measures are as follows:
A. cage revolution motion stability, should as far as possible by the ring guide way and pay attention to guide the full lubrication, give the improvement of bearing structure of high speed conditions, the L type roller guide holder is changed to Z type ring ribguide holder.
B. bearings rotate at high speed, bearing pocket clearance of the cage vibration amplitude is much larger than the pocket hole cage vibration amplitude gap is small,so the pocket clearance value is very important.
C. should pay attention to reduce the radial clearance.
D. try to improve manufacturing precision frame maintain, improve the surface quality of the holder, helps to reduce body roll and keep the noise frame collision or friction.
E. actively adopt advanced cleaning technology, cleaning effective parts and the setof products, improving the cleanliness of bearing.
5 by rolling vibration
When the operation of the bearing under a radial load, its internal only a plurality ofrolling load, due to the ferrule elastic contact constitute the "spring" supporting therolling body in the radial load line generates periodic oscillation, and the shaft centerwill therefore vertically moving or moving horizontally, and causes noise. This kind of vibration is called rolling through the vibration, especially in low speed when the more obvious.
And the amplitude is related to bearing type, radial load, radial clearance and ballnumber. Usually the smaller amplitude, if the amplitude is large when the harm, this is often the minish preload appropriate axial clearance or to reduce.